Fuel injecting carburetor

ABSTRACT

There is disclosed a fuel injector for internal combustion engines having a rectangular throat and a valve in the throat having a gate located in the throat between air intake and outlet chambers, the gate being mounted to slide across the throat by operation of an accelerator to control the quantity of air passing through the throat to the intake manifold, there being a series of fuel jet ports in the throat arranged to be opened successively as the valve gate opens and closes the throat to eject fuel into the air stream passing through the throat, the proportion of air and fuel once determined being constant through the full range of acceleration and deceleration of the engine. The proportion may be varied by controlling the output pressure of a pressure regulato between the fuel supply and the carburetor.

United States Korponay atent 1 1 1451 Aug. 14, 1973 FUEL INJECTING CARBURETOR 3,682,449 8/1972 Severn 261/62 [76] inventor: 3331:1532 22 Corona Dr., primary Examiner .nm R. Miles Attorney-Arthur A. Johnson [22] Filed: Aug. 6, 1971 [21] Appl. No.: 169,783 [57] TB There 1s d sclosed a fuel ln ector for lntemal combustion engines having a rectangular throat and a'valve in U-S. B, R the throat having a gate located in the throat between [51] Int. Cl. F02m 9/06 air i k d tl t chambers, the gate being mounted [58] Field of Search 261/41 3! 44 62 to slide across the throat by operation of an accelerator to control the quantity of air passing through the throat [56] References Cited to the intake manifold, there being a series of fuel jet UNITED STATES PATENTS ports in the throat arranged to be opened successively 1,125,069 1/1915 Coulter 261/41 B as the valve s Opens and closes the throat to ejct 1,489,639 4/1924 Hough 261 /41 B fuel into the air stream passing through the throat, the 2,091,566 8/1937 Portes 261/41 B proportion of air and fuel once determined being cons- 3,086,758 i963 Greene 1/ R tant through the full range of acceleration and deceler- 3,l81,5l9 5/1965 D0128 261/51 X ation of the engine The proportion may be varied g 5;; controlling the output pressure of a pressure regulato weeney... 3,439,903 4/1969 TOlIlai 261/50 A between the fuel Supply and the carburemr' 3,680,535 8/1972 Eckert et al. 261/50 A 1 Claim, 8 Drawing Figures 75 1a /8 T fi 45 4 3 l5 r4 4/ m 20 Y L .1, ,1 :75 ,29 I 1 t 1 56 t 28 j? t A I 6, LA x 3 19 PAIENIEmus 14 ms 3352.454

sum 1 or 3 I FUEL INJECTING CARBURETOR This invention relates to improvements in fuel injecting carburetors for internal combustion engines.

Anobjectof the present invention is to provide a simple, efficient fuel injection type carburetor in which the desired proportion of the fuel to the air in the mixture passing through the carburetor and delivered to the intake manifold of the engine is maintained substantially constant through the entire range of speed variations, from idling speed to maxiumum speed, whereby smooth changes in speed, may be hadwhen accelerating and decelerating the engine.

This is accomplished, according to the present invention, by providing anair intake passage or throat for the carburetor, which is rectangular in cross-section, and a square-edged valve gate which is movable across the throat in a line perpendicular to the direction of the air stream, so that in each increment of movement of the gate an equal amount of air is added to or subtracted from the air stream flowing through the. throat to the intake manifold, according to whether the movement of the gate is in the opening or in the closing direction.

For-the same purpose, in the form of the invention herein disclosed, the fuel which is fed at a determinate pressure directly to the carburetor is injected into the air stream from one or more jet tubes having one or more rows of closely. equispaced jet ports extending from the gateacrossthe throat, the jet ports being successively opened or closed to control the quantity of fuel injected into the air stream in fixed coordination with the opening: and closing movements of the gate valve.

An important feature of this invention is the provision of means whereby the proportion of the airto-fuel mixture passing to the intake manifold may be varied for the purpose of tuning the engine, or obtaining economy ofoperationthereof, or to obtain full'power, or to adjust the-air-fuelmixture to ambient conditions in the locality in which the engine ismost frequently used.

These advantages are obtained by adjusting a fuel pressureregulator to increase or decrease pressure of the fuelflowingto the jet ports and thereby increase or decrease the amountof fuel issuing from the jets.

Another feature of this invention is the provision of a carburetor, of the fuel injection type, which does not require the use of a float chamber for the fuel and hence maybe directly connected to a pressure regulator, or a needle valve to control the amount of fuel delivered tothe mixing chamber. Further, the carburetor of this invention does not require the use of a butterfly valve to control the amount of air-fuel mixture delivered to the intake manifold of the engine, therebyavoiding the trouble which occurs when a butterfly valve freezes.

Another feature of this invention is the provision of a fuel injecting type of carburetor which is sturdy yet simple in construction and has substantially less parts than carburetors heretofore proposed.

A further feature is the provision of fuel injecting means which are so located as to inject fuel directly into athroat portion of the carburetor which is controlled by a gate valve.

Other features and advantages will hereinafter appear.

' In the accompanying drawings:

FIG. 1 is a top plan view of thecarburetor of the present. invention showing the air intake orifice and the air throttling valve gate in closed position;

FIG. 2 is a vertical cross-section. taken. on the line 2-2 of'FIG. 1;

FIG. 3 is a transversecross-section taken on the line 3-3 of FIG. 2;

FIG. 4 is a plan. view of the upper side of the bottom part of the body of the carburetor showing the ball bearings on which the valve gate rides;

FIG. 5 is a plan view of the bottom side of the upper part: of the body of the carburetor;

FIG. 6' is a view similar to FIG. I but showing the valve gate partly closed and only part of the jet ports p FIG. 7 is a fragmentary view, partly in. section, of a portion of FIG. 6 on a large scale to show details of the carburetor more clearly; and

FIG. 8 is a sectional view taken on the line 8-8 of FIG. 6 of the means for adjusting the flow of fuel to the auxiliary jet port.

As shown in the accompanying drawings, which illustrate one embodiment of this invention, that at present preferred, the fuel injecting carburetor comprises a body 10' having twosuperposed plate-like parts comprisingan upper part 11 and a lower part 12 which may besecured together inface-to-facerelation by screws 10a; Theupper part 1-1 has-an air intake passage 13 and is adapted to receive screws 14 by means of which: it may have secured toit an air cleaning device such as the air cleaner 15', part of which is shown in FIG. 2.

The lower body part 12 has an" air and fuel mixing and delivery chamber 1 6 axially aligned with and forming a continuation of the air'intake passage 13. The ad'- jacent portions of the passage 13 and chamber 16 form a throat 17 through which intake air must pass. The lower body part 1-2 is provided with screw holes to receive screws 18 for fastening the body 10 to the intake manifold 19 of an internal combustion engine indicated in FIG. 2.

Accordingto the present invention, fuel is fed to the injector under determinate pressure from a fuel pump and pressure regulator by fuel pipes 22 and flttings23 connected to the body part 11 so as to communicate with one or'more longitudinally extending fuel ducts 24 opening at one end at the throat 17 in the body part 11.

The flow of air from the intake passage 13 through the throat 17 to the mixing chamber 16 is controlled'by a valve gate 26 slidably mounted in a cavity 27 in the body partl landis sandwiched between the body parts 11 and 12. The valve gate 26 has an imperforate portion 28 adapted, inone position of the gate 26, to completely close the throat 1-7 against the passage of air to the mixing chamber 16,.and'an aperture or passageway 29 having an area which conforms approximately to the cross-sectional area of the throat l7 and aligns with the latter when the gate 26 is in completely openposition.

The throat 17 is opened and closed more or less to control the passage of air from the intake chamber 13 through the throat l7 to the mixing chamber 16 by adjusting the longitudinal position of the gate 26 relative to the chambers by operation of a Bowden wire 30, or other operating connection, to an accelerator pedal, or other means controlled by the operator, against the tension ofa suitable resilient return means which will cause the gate 26 to move in throat-closing direction.

In the form shown, this return movement of the gate 26 is accomplished by springs 31 which are guided on pins 32 secured to the end 33 of the body part 11 and extend into holes 34 in the gate 26 to urge the gate 26 to the left to gate-closing position, as viewed in FIGS. 1 and S.

In order to meter the fuel supplied by the ducts 24, and hence the mixture of air and fuel passing to the intake manifold of the engine, each fuel duct 24 slidably receives a jet tube 35 which is open at one end to communicate with its duct 24. Each jet tube 35 is secured at its other end to the edge portion 36 of the gate 26 so as to project into the passageway 29 and be in alignment with its duct 24. The jet tubes 35 are adapted to extend into the ducts 24 more or less depending on the position of the passageway 29 in the gate 26 relative to the throat 17.

As shown herein, each jet tube 35 is provided with one or more, preferably two, longitudinally extending rows of jet ports 37 which are covered, i.e., closed, when its jet tube 35 is located in its duct 24, and this occurs when the imperforate portion 28 closes the throat 17 with the result that no fuel is at that time ejected from the jet ports 37.

Since the jet tubes 35 are connected to the gate 26 for movement therewith, the jet ports 37 become exposed or open progressively when the jet tubes 35 are withdrawn from the ducts 24 to increase the supply of fuel to the air stream in the throat I? as the quantity of the air stream increases. Likewise, when the gate 26 is moved to decrease the volume of the air stream passing through to the throat, the movement of the jet tubes 35 into the ducts 24 causes the latter to cover or close the jet ports 37 successively. When the throat 17 is completely closed by the gate 26, the jet ports 37 are completely covered.

While a plurality of tubes 35 are referred to herein, it should be understood that it is within the spirit and scope of this invention to provide only one duct and jet tube, if desired.

According to the present invention, smooth acceleration and deceleration of the engine may be accomplished by providing for the maintenance of a substantially constant determinable proportion of the air-tofuel mixture entering the intake manifold 19 at all speeds at which the engine is designed to operate.

This is accomplished by designing the carburetor for a particular engine so that, for each increment of the operator-controlled movement of the accelerator and hence of the gate 26, one or a predetermined number of the jet ports 37 will be opened or closed depending on the diameter of the jet ports and the effective crosssectional area of the throat 117 with the gate 26 in determinate position.

To obtain straight line increase and decrease of the air stream, the intake passage 13, or at least the throat portion 17 and the passageway 29 in the gate 26, are made rectangular as shown so that for each increment of movement of the gate 26 the effective area of the throat 17 will be changed by the same amount.

In most situations the jet ports 37 may be closely equispaced in the tubes 35, so that a substantially straight line increase or decrease of the quantity of fuel injected may be obtained, with a straight line increase and decrease in the effective area of, the throat 17. However, in the broader aspects of this invention, if desired, the size of the jet ports mayvary from one end of the row to the other, or the spacing between the respective jets may progressively change from one end of each row to the other to effect the gradual increase in richness of the mixture as the gate opens the throat. In most cases, however, it is desirable, as pointed out above, to maintain the proportion of the air-to-fuel mixture entering the intake manifold substantially constant for all speeds for which the engine is designed. When this is done, the acceleration and deceleration of the engine is gradual and smooth.

As shown herein, the rows ofjet ports 37 are so positioned on opposite sides of each jet tube 35 that jets of fuel issuing from the ports 37, when the latter are open, travel'in a direction perpendicular to the direction of travel of the air stream through the throat 17 so that the fuel jets are picked up by the air stream and volatilized as they pass into the mixing chamber 16. When a plurality of ducts 24 and jet tubes are employed, the jet tubes 35 are preferably in parallel rows and are so spaced from each other and the adjacent walls of the passageway 29 that the distribution of fuel in the mixing chamber is substantially uniform.

In starting the engine with the carburetor of the present invention, when the crank shaft of the engine is rotated by the starter, the driver operates the accelerator to move the gate 26 to the right as shown in FIG. 1, and thereby partially withdraws the tubes 35 from the ducts 24 to' cause several of the jet ports to be open and, at the same time, to move the imperforate portion 28 of the gate partially away from the throat 17. When the crank shaft is rotated, suction produced by the operation of the pistons causes an air stream to pass through the passageway 29 and throat l7 and into the mixing chamber 16. At the same time, due to the operation of the fuel pump and pressure regulator supplying fuel to the carburetor, fuel is caused to flow into the ducts 24 and tubes 35 and be ejected through the jet ports 37 which have been opened into the air stream to be volatilized and drawn with the air into the mixing chamber and intake manifold of the engine.

After the engine is thus started, the speed of the engine may be increased by further opening movement of the gate 26 against the tension of the springs 32 to cause more of the jet ports 37 to be open and the effective size of the throat 17 to be increased, so that a greater amount of air-fuel mixture will be fed to the intake manifold and the cylinders. To decrease the speed of the engine, the gate 26 is allowed to close more or less, and a greater or lesser number of jet ports to be closed.

When the gate 26 ultimately and completely closes the throat 17, the tubes 35 will be completely retracted into the ducts 24.

In order to prevent any fuel in the ducts 24 from seeping around the tubes 35 and dripping into the chamber 13 when the throat 17 is closed, the portion 36 of the gate 26 to which the jet tubes 35 are attached is provided with gaskets 39 positioned to engage and stop-off the ends of the ducts 24.

In the broader aspects of this invention, when the jet ports 37 are on opposite sides of a jet tube 35, they may be in alignment transversely of the tube. However, it has been found advantageous to have the jet ports on opposite sides of a tube 35 staggered as shown in FIG. 7 so that, in each increment of advancing or retracting movement of the tube, only one additional jet port of each tube 35 is opened or closed, thus providing for a fine control of the fuel and gas mixture entering the intake manifold of the engine.

The present invention provides means for allowing the engine torun at idling speeds when the ignition system continues to function and the accelerator is released by the operator. For this purpose, the present invention provides stop means for limiting the closing movements of the gate valve to allow a sufficient amount of air and fuel mixture to enter the intake manifold for idling purposes and provides further that, when the ignition is turned off and suction from the cylind ers ceases, the gate 26 may finish its movement to completely close the jet ports and the passageway 29.

This is accomplished by providing on the body part 11 a stop pin 40 which is mounted in a sleeve 41 which is screwed into a threaded hole 1 la in the body part 11. The inner end 42 of the stop pin 40 is in position to be engaged by the surface 43 on the end of the gate and prevents the gate from completely closing. The outer end 44 of the pin 40 is connected by a link 45 to a suction-operated device 46 which is connected by tubing 47 to a passage 48 in the body part 12 (see FIG. 4) which opens into the mixing chamber 16.

The diaphragm of the suction device 46 and the link 45 are spring-biased to withdraw the end 42 of the pin 40 from engagement with the surface 43 of the gate to allow the gate to completely close. However, so long as the engine is running, the suction created in the device 46 causes the end 42 of the pin to remain in the path of the gate.

In order to adjust the idling speed of the engine, the end 42 of the pin 40 is tapered and the surface 43 of the gate is inclined so thatby moving the pin 40 inwardly or outwardly the gate 26 may be arrested in more or less open position.

The operative position of the pin 40 is controlled by a shoulder 40a in the pin 40 engaging the bottom 48 of a cavity 49 in the sleeve 41. By screwing the sleeve 41 more or less in the threaded hole 1 la, the end of the pin may be moved relative to the inclined surface 43 of the gate and thus cause the idling position of the gate to be more or less open.

A spring 50 between the flange 51 on the sleeve 41 and the body part I 1 holds the sleeve 41 in adjusted position.

For the purpose of further tuning the engine so that it idles smoothly, the present invention provides means for supplying an auxiliary amount of fuel to the throat 17. As shown, this means comprises a lug 52 on the part 11 which projects into the throat l7 and has an auxiliary jet port 53 opening into the throat 17 when the gate is moved to allow the air stream to flow into the mixing chamber.

Fuel may befed to the auxiliary jet port 53 in any suitable way. As shown herein, the jet port 53 commu- 'nicates with a vertical passage 54 in the lug 52 and the passage 54 communicates with a horizontal passage 55 which connects with a fitting 56 adapted to receive piping connected to the fuel regulator.

To regulate the fuel flowing to the jet port 53, there is provided a valve needle 57 which extends through an opening 58 in alignment with the passage 55. The end of the needle 57 which extends outside the body part 11 is provided with an adjusting knob 57a threaded in the body part. By rotating the knob 57a in one direction, the tapered end of the needle 57 is caused to project more or less into the opening 58 and control the amount of fuel passing to the auxiliary jet 53, and thus control the idling speed of the engine. A spring 57b between the adjusting knob 57a of the needle valve and the body part 11 prevents the needle valve from inadvertently shifting.

The lug 52 projects into the space between the body part 11 and the gate 26, which has a notch 60 to clear it.

In the carburetor of the present invention, fuel is fed to the jet ports 37 and auxiliary jet port 53 under determinate pressure controlled by the pressure regulator.

If it should be desired to produce a richer or leaner air-fuel mixture for starting the engine or for any other purpose, this may be accomplished by merely adjusting the variable pressure regulator to increase or decrease the pressure at which the fuel is injected into the air stream passing through the throat 17. This will of course change the proportion of the ai'r-to-fuel in the mixture, but this will not affect the ability of the carburetor of this invention to maintain the desired proportion of air-to-fuel mixture over the full range of movement of the gate valve and jet tubes.

To provide for conveniently making adjustment to the pressure regulator, Bowden wire or other connecting means may be provided between the pressure adjusting means on the regulator and an adjusting knob located on the instrument panel or other available place so that the pressure regulatormay be adjusted from the drivers seat. The pressure regulator may also be adjusted by heat-activated means.

In case of any difficulty in starting the engine due to climatic conditions, the operator may temporarily adjust the fuel pressure to produce a richer or leaner mixture.

It has been found that, when the gate 26 is not in full open position, the pressure of the air on the upstream side of the gate 26, due to the partial vaccum created under the gate by operation of the cylinders of the en-- gine, forces the gate against the upper surface of the part 12 with such force that it is difficult, if at all possible, to move the gate when accelerating and decelerating, and would require a large amount of operatorapplied force when accelerating and powerful springs 31 when decelerating.

' To avoid this difficulty, the present invention provides antifriction means in the form of ball bearings 59, see FEGS. 3 and 4, between the bottom of the gate 26 and the upper surface of the body part 12. In the form shown, the ball bearings 59 are carried by straight races 60 and ride in grooves 61 in the body part 12, each ball riding on the bottom of the groove 61 and the bottom of the gate 26.

Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.

I claim:

1. Fuel injecting means for internal combustion engines comprising a body having an air intake passage; an air and fuel mixing and delivery chamber having a rectangular throat portion between said intake passage and said chamber through which an air stream passes to the intake manifold of an engine; means for delivering fuel under pressure to the body including a plurality of parallel fuel duct means fixed to and extending through said body in the direction toward said throat portion and each having an open end terminating at one straight edge of said rectangular throat portion;

valve means including a plate forming a gate slidably mounted on said body for movement to and from closed position across said throat portion to control said air stream quantitatively, said gate having a leading straight edge parallel to and engageable with said straight edge of said throat portion at which said fuel duct means terminate, said means for delivering fuel including fuel metering and injecting means including a plurality of parallel jet tube means secured to said leading straight edge of said gate and extending into and substantially coextensive with said fuel duct means in longitudinal sliding engagement therewith; gasket means positioned between said leading edge of said gate and said body where said fuel duct means terminate to prevent the escape of fuel from the ends of said fuel duct means when the gate is in closed position, said jet tube means each having at least one longitudinally extending row of jet ports for injecting fuel under pressure into and transversely across said throat portion when drawn out of said fuel duct means by said gate; and accelerator operated means operatively connected to said gate for causing a greater or lesser number of said jet ports to pass beyond the end of said fuel duct means and cause a determinate quantity of fuel to be injected from said jet ports into said throat portion and for simultaneously causing the gate to be moved by said accelerator means toopen and close said throat a determinate extent. 

1. Fuel injecting means for internal combustion engines comprising a body having an air intake passage; an air and fuel mixing and delivery chamber having a rectangular throat portion between said intake passage and said chamber through which an air stream passes to the intake manifold of an engine; means for delivering fuel under pressure to the body including a plurality of parallel fuel duct means fixed to and extending through said body in the direction toward said throat portion and each having an open end terminating at one straight edge of said rectangular throat portion; valve means including a plate forming a gate slidably mounted on said body for movement to and from closed position across said throat portion to control said air stream quantitatively, said gate having a leading straight edge parallel to and engageable with said straight edge of said throat portion at which said fuel duct means terminate, said means for delivering fuel including fuel metering and injecting means including a plurality of parallel jet tube means secured to said leading straight edge of said gate and extending into and substantially coextensive with said fuel duct means in longitudinal sliding engagement therewith; gasket means positioned between said leading edge of said gate and said body where said fuel duct means terminate to prevent the escape of fuel from the ends of said fuel duct means when the gate is in closed position, said jet tube means each having at least one longitudinally extending row of jet ports for injecting fuel under pressure into and transversely across said throat portion when drawn out of said fuel duct means by said gate; and accelerator operated means operatively connected to said gate for causing a greater or lesser number of said jet ports to pass beyond the end of said fuel duct means and cause a determinate quantity of fuel to be injected from said jet ports into said throat portion and for simultaneously causing the gate to be moved by said accelerator means to open and close said throat a determinate extent. 